PTL 1 discloses a shutter device where two shutter-blades open and close an opening by a stepping motor rotationally driving a drive ring.
The shutter device disclosed in PTL 1 has formed an acceleration region where rotating the drive ring does not cause the two shutter blades to open and close the opening, and an exposure region where rotating the drive ring causes the two shutter blades to open and close the opening. The shutter device disclosed in PTL 1 accelerates the stepping motor in the acceleration region, and thereafter the two shutter blades open and close the opening in the exposure region.